Patent Document 1 discloses a seat structure in which a cushioning member such as a three-dimensional knitted fabric (three-dimensional net member) is disposed across a cushion frame of a seat cushion part. In the seat structure in which the cushioning member is thus disposed across the cushion frame, a base net (note that, in the present specification, the simple expression of a “cushioning member” of a seat cushion part means the cushioning member including the base net disposed as a lower layer thereof) such as a three-dimensional knitted fabric or a two-dimensional fabric is provided via an elastic member for the purpose of preventing bottom touch and increasing a vibration absorbing characteristic and so on. In Patent Document 1, torsion bar units each including a torsion bar, arms coupled to the torsion bar and rotatably supported on the torsion bar as a fulcrum, and a support frame supported by the arms are disposed in front of and behind a seat cushion, and the base net is stretched between the support frame of the front torsion bar unit and the support frame of the rear torsion bar unit to be elastically supported.